Ever wonder what would happen if a relief valve failed or was plugged? This short video on Youtube from Mythbusters shows just what can happen. These guys constructed a mock up of a 2 story house and set a 53 gallon electric water heater in what would be the basement. They plugged the relief valve and monitored the temperature and pressure from a safe distance. What happened a few minutes later will amaze and frighten you at the same time.
